package com.topit.show.core.util;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang.StringUtils;

public class EmojiFilter {

	/**
	 * 检测是否有emoji字符
	 * 
	 * @param source
	 * @return 一旦含有就抛出
	 */
	public static boolean containsEmoji(String source) {
		if (StringUtils.isBlank(source)) {
			return false;
		}
		int len = source.length();
		for (int i = 0; i < len; i++) {
			char codePoint = source.charAt(i);

			if (isEmojiCharacter(codePoint)) {
				// do nothing，判断到了这里表明，确认有表情字符
				return true;
			}
		}
		return false;
	}

	private static boolean isEmojiCharacter(char codePoint) {
		return (codePoint == 0x0) || (codePoint == 0x9) || (codePoint == 0xA) || (codePoint == 0xD) || ((codePoint >= 0x20) && (codePoint <= 0xD7FF)) || ((codePoint >= 0xE000) && (codePoint <= 0xFFFD)) || ((codePoint >= 0x10000) && (codePoint <= 0x10FFFF));
	}

	/**
	 * 过滤emoji 或者 其他非文字类型的字符
	 * 
	 * @param source
	 * @return
	 */
	public static String filterEmoji(String source) {
		if (!containsEmoji(source)) {
			return source;// 如果不包含，直接返回
		}
		// 到这里铁定包含
		StringBuilder buf = null;
		int len = source.length();
		for (int i = 0; i < len; i++) {
			char codePoint = source.charAt(i);
			if (isEmojiCharacter(codePoint)) {
				if (buf == null) {
					buf = new StringBuilder(source.length());
				}
				buf.append(codePoint);
			} else {
			}
		}
		if (buf == null) {
			return source;// 如果没有找到 emoji表情，则返回源字符串
		} else {
			if (buf.length() == len) {// 这里的意义在于尽可能少的toString，因为会重新生成字符串
				buf = null;
				return source;
			} else {
				return buf.toString();
			}
		}

	}

	public static String emojiFilter(String str) {
		String patternString = "([\\x{10000}-\\x{10ffff}\ud800-\udfff])";

		Pattern pattern = Pattern.compile(patternString);
		Matcher matcher = pattern.matcher(str);

		StringBuffer sb = new StringBuffer();
		while (matcher.find()) {
			try {
				matcher.appendReplacement(sb, "[[EMOJI:" + URLEncoder.encode(matcher.group(1), "UTF-8") + "]]");
			} catch (UnsupportedEncodingException e) {
				e.printStackTrace();
			}
		}
		matcher.appendTail(sb);

		return sb.toString();
	}

	public static String emojiRecovery(String str) {
		String patternString = "\\[\\[EMOJI:(.*?)\\]\\]";

		Pattern pattern = Pattern.compile(patternString);
		Matcher matcher = pattern.matcher(str);

		StringBuffer sb = new StringBuffer();
		while (matcher.find()) {
			try {
				matcher.appendReplacement(sb, URLDecoder.decode(matcher.group(1), "UTF-8"));
			} catch (UnsupportedEncodingException e) {
				e.printStackTrace();
			}
		}
		matcher.appendTail(sb);

		return sb.toString();
	}
}